// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/callback_internal.h"

#include "base/logging.h"

namespace base {
namespace internal {

    namespace {

        bool ReturnFalse(const BindStateBase*)
        {
            return false;
        }

    } // namespace

    BindStateBase::BindStateBase(InvokeFuncStorage polymorphic_invoke,
        void (*destructor)(const BindStateBase*))
        : BindStateBase(polymorphic_invoke, destructor, &ReturnFalse)
    {
    }

    BindStateBase::BindStateBase(InvokeFuncStorage polymorphic_invoke,
        void (*destructor)(const BindStateBase*),
        bool (*is_cancelled)(const BindStateBase*))
        : polymorphic_invoke_(polymorphic_invoke)
        , ref_count_(0)
        , destructor_(destructor)
        , is_cancelled_(is_cancelled)
    {
    }

    void BindStateBase::AddRef() const
    {
        AtomicRefCountInc(&ref_count_);
    }

    void BindStateBase::Release() const
    {
        if (!AtomicRefCountDec(&ref_count_))
            destructor_(this);
    }

    CallbackBase<CopyMode::MoveOnly>::CallbackBase(CallbackBase&& c) = default;

    CallbackBase<CopyMode::MoveOnly>&
    CallbackBase<CopyMode::MoveOnly>::operator=(CallbackBase&& c)
        = default;

    CallbackBase<CopyMode::MoveOnly>::CallbackBase(
        const CallbackBase<CopyMode::Copyable>& c)
        : bind_state_(c.bind_state_)
    {
    }

    CallbackBase<CopyMode::MoveOnly>& CallbackBase<CopyMode::MoveOnly>::operator=(
        const CallbackBase<CopyMode::Copyable>& c)
    {
        bind_state_ = c.bind_state_;
        return *this;
    }

    void CallbackBase<CopyMode::MoveOnly>::Reset()
    {
        // NULL the bind_state_ last, since it may be holding the last ref to whatever
        // object owns us, and we may be deleted after that.
        bind_state_ = nullptr;
    }

    bool CallbackBase<CopyMode::MoveOnly>::IsCancelled() const
    {
        DCHECK(bind_state_);
        return bind_state_->IsCancelled();
    }

    bool CallbackBase<CopyMode::MoveOnly>::EqualsInternal(
        const CallbackBase& other) const
    {
        return bind_state_ == other.bind_state_;
    }

    CallbackBase<CopyMode::MoveOnly>::CallbackBase(
        BindStateBase* bind_state)
        : bind_state_(bind_state)
    {
        DCHECK(!bind_state_.get() || bind_state_->ref_count_ == 1);
    }

    CallbackBase<CopyMode::MoveOnly>::~CallbackBase() { }

    CallbackBase<CopyMode::Copyable>::CallbackBase(
        const CallbackBase& c)
        : CallbackBase<CopyMode::MoveOnly>(nullptr)
    {
        bind_state_ = c.bind_state_;
    }

    CallbackBase<CopyMode::Copyable>::CallbackBase(CallbackBase&& c) = default;

    CallbackBase<CopyMode::Copyable>&
    CallbackBase<CopyMode::Copyable>::operator=(const CallbackBase& c)
    {
        bind_state_ = c.bind_state_;
        return *this;
    }

    CallbackBase<CopyMode::Copyable>&
    CallbackBase<CopyMode::Copyable>::operator=(CallbackBase&& c)
        = default;

    template class CallbackBase<CopyMode::MoveOnly>;
    template class CallbackBase<CopyMode::Copyable>;

} // namespace internal
} // namespace base
